Field of the Invention
The present invention relates to a display device and an image rendering method thereof in consideration of a saturation of a text image.
Discussion of the Related Art
Flat panel display devices such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a field emission display (FED) and a plasma display panel (PDP) are known.
A rendering algorithm converts data of an input image into data suitable for the pixel arrangement and structure of a display panel when the resolution of the input image differs from the physical resolution of the display panel. Such a rendering algorithm is applied to display devices.
When the resolution of an input image is different from the resolution of the display device, the quality of an image reproduced by the display device may deteriorate. It may not be difficult to process the input image into a high resolution image without loss of picture quality. However, when the resolution of the input image is converted into a lower resolution image matching the physical resolution of the display device, and the input image is reproduced with the converted resolution through the display device, a data distortion or loss may occur and thus, the picture quality may deteriorate.
Particularly, when a text in the input image is reproduced through a display device having a lower resolution than the input image, text legibility may deteriorate due to an omission or distortion of the data constituting the text. Various rendering algorithms have been proposed in order to enhance text legibility when the resolution of the display device is lower than that of the input image. The applicant proposed a rendering algorithm for improving text legibility in consideration of a difference between neighboring pieces of data when the resolution of a display device is lower than that of an input image (Korea Patent Application 10-2013-0139770 filed on 2013 Nov. 18).
When a text data is converted using conventional rendering algorithms, the legibility of the text data may deteriorate. Particularly, conventional rendering algorithms typically do not consider the saturation of text, focusing on an achromatic text data. Accordingly, the legibility of chromatic data may further deteriorate when conventional rendering algorithms are applied.